Safety lock



June 9, 1931. A. MAIRE ET AL 1,809,486

SAFETY LOCK Filed Dec. 17, 1928 Patented June 9, 1931 UNITED STATESPATENT OFFICE ALFRED MAIRE, OF ST. IMIER, AND ARMAND BEGUELIN, OF RENAN,SWITZERLAND SAFETY LOCK Application filed December 17, 1928, Serial No.

The present invention relates to safety locks of the kind having a droplatch engaged into a striking plate and a handle which in order to liftthe latch must first be turned for a certain number of steps alternatelyin a clockwise and an anticlockwise direction before it can catch saidlatch so as to lift and release it.

The annexed drawings represent as an example one working form of theobject of the invention.

The Fig. 1 shows the lock and the latch in a front elevation.

Fig. 2 is a cross section of the same.

The Figures 3 and 4 represent the first an inside view of the lockhaving the front cover removed and the second is a front view of thebottom of the casing.

The Figures 5, 6 and 7 are front view, end View and back view of a diskcarrying the coupling members between the latch and the handle.

The casing 1 of the lock is cylindrical and comprises a bottom 2, anannular body 3 and a cover 4. A shaft 6 having a handle 5 securedthereto is rotatably held in central holes of the bottom and the coverand is rigidly connected to a disk 7 arranged between the cover and thebottom. This disk 7 has two segmental parts cut oil on two diametricallyopposite sides and on two parallel lines, a smaller cut 21 and a largercut 22. In the body of the disk is slidingly lodged a short pointed pin8 projecting normally under the effect of a spring into the smaller cut21 of the disk so as to be transiently engaged into the notches 9provided inside of the annular body 3. The said notches mark the stepswhich are to be made when turning the button 5. This button has on itscircumference as many circular notches 9 as there are notches 9 andbesides a guiding mark 20 on the side facing the lock. Another pin 10 isslidingly lodged in the body of the disk 7 but not in the same verticalplane perpendicular to the axis and in a stepped part of said disk ofsmaller diameter. Said pin carries two cross-pegs whereof the one 12 isguided within a slot on the back side of the disk 7 while the other peg326,532, and in Switzerland January 4, 1928.

11 is guided in another slot on the front side of said disk. The slidingpin 10 is under the effect of a spring 13 and is normally maintained bythis spring in such a position that the peg 12 is near the periphery ofthe disk 7 while the other peg 11 is near the center of the disk. At itsone end this pin 10 is provided with a nose 14 which projects over theperiphery of that part of the disk 7. This nose 14 is in the path ofanother nose 15 fixed to the annular body 3. Now when shaft 6 is turnedby means of the button 5 the two noses will meet and pin 10 be pushedback displacing thereby also the pegs 11 and 12.

The bolt 16 of the lock is located between disk 7 and cover 4 and isheld loose on the shaft 6. It touches the surface of the disk, but isrecessed on a certain part 17 so that the peg 11 may pass beneath itwhen the disk is rotated. While the length of peg 12 must be sufficientfor having this peg guid ed wlthin the grooves 18, which are describedhereafter, and while this peg 12 has to travel gradually towards thecenter the peg 11 will move outwardly. The length of this peg 11 is sochosen that when the disk 7 is rotated the peg will pass freely throughthe recessed portion 17 of the latch as long as it has not yet reachedits extreme outward position. When in this position however it will meetthe nonrecessed portion of the latch and be able to move this latch soas to lift it.

On the inside of the bottom wall 2 of the casing 1 a number of circulargrooves are arranged concentrically into which are fixed springy steelblades 18 leaving canals between them available as guides for the peg12. The said blades are not extended over the whole circumference of thegrooves but only on certain sectors corresponding in length to a certainnumber of the steps marked by the notches 9. Besides a certain leg 19 ofeach of these blades is flexible and touches the next outer blade as toblock the passage between the two respective blades. The Whole of theblades constitutes a labyrinth having passages the length of whichexpressed in numbers of steps corresponds to a combination of numeralsthe knowledge of which allows to open the lock.

The working of the latch by means of the handle 5 is as follows:

The handle is first turned into a position determined by the guidingmark 20 and known only by the person initiated into the secret. Thisposition is given in the Figures 3 and 4 and shows the nose 14 touchingthe nose 15 from underneath. The back wall 2 considered as a dial hasbeen divided in eight sectors by means of radial incisions andcorresponding with the division of the notches 9.

The shaft 6 is now turned to the left in Fig. 4 as indicated by thearrows first in the direction of the outer arrow. By this movement nose14 will be pushed back by nose 15 so as to bring peg 12 before theentrance of the outer passage. Vhile continuing the turning movement aslight resistance will be felt every time when the pin 8 passes thenotches marking the steps of the movement. Having passed four steps thatis as many steps as is indicated by the first numeral of the combinationnumber the shaft is turned backwards to the right as indicated by themedian arrow and is turned 4 steps that is as many steps as indicated bythe second numeral. During this backward movement peg 12 will travel inthe outermost passage but one becauseat the end of the outermost passageit hadpushed the leg 19 aside and when returning had been directed bythe same leg into the next passage nearer to the center. Thus by turningshaft 6 alternately forward and backward every time for the number ofsteps prescribed by the combination number the peg 12 will move with thefourth movement into the innermost passage next to the center and nextto the outlet of the blade system butthen to the contrary peg 11 willhave moved the farthest from the center and have passed beyond therecessed part 17 of the latch 16 so that with the second backwardsmovement that is with the fourth turning movemelit of the shaft duringwhich peg 12 is maintained near the center, the latch will be caught atthe non recessed portion by the peg 11 which has travelled now farenough outwardly in a radial direction. By a. continued turn ofthe'handle the latch will be lifted and released from the strikingplate, which has not been represented in the drawings. In this casetherefore as shown in Fig. 4 the combination number will be 4432. Thisnumber besides the knowledge of the starting point must be known bythose who want to open this lock. It will be easily understood thatinstead of arranging the lock with four blades and for a combinationnumber having four numerals Y the number of blades could be increased orbe decreased and that also the number of divisions on the bottom plate 2could be more or less than eight and also the position of the guidingmark 20 could be changed.

If it is wanted to lock the latch again shaft 6 has to be turned severaltimes backward again. Then the peg 11 will come to interrupted parts ofthe blades whereby under the effect of spring 13 pin 10 will at onceassume again its initial position of rest. Thereby the latch 16 isrendered again independent from any further movement of the button 5.

What we claim as new is:

1. In a safety lock and in combination a casing having an annular rimprovided with an inside division marked with notches, a projecting shaftwith a handle arranged concentrically to said division and rotatable "insaid casing and constituting the locking and unlocking means. a similardivision like the first and a guiding mark provided on said handle, arotatable member fittin said annular rim and secured to said sha t, ashort pointed pin lodged resiliently in said member and adapted to markthe steps taken by said member while passing said notches of the rim, :1slidable pin carrying two cross pegs projecting on opposite sides, saidpin being resiliently mounted in said member having a nose pro ectingbeyond the periphery of the member, a stationary nose secured to thesaid rim and projecting in the path of the first nose, a latch heldloose on the shaft close beside the said member and having a recessedpart on the side of this member in the path of the respective peg ofsaid slidable pin and a labyrinth of springy blades arrangedconcentrically to the shaft and forming a number of passages for thesecond peg on the bottom of the casing and arranged so as to constitutea guide for said peg and for the sliding pin in order to bring the firstpeg in contact with the non recessed part of the latch so as to releaseit from its catch.

2. In a safety lock and in combination a casing having an annular rim, aprojecting shaft having a handle located concentrically to said rim androtatable in said casing and constituting the locking and unlockingmeans, a rotatable member fitting said annular rim and rigidly securedon said shaft, a pin fitted slidably in said member and hav ing a noseprojecting beyond the periphery of the member, a spring arranged so asto hold said pin in an initial position of rest, two cross pegs fixed tosaid pin and projecting at opposite ends and on opposite sides to theoutside of said rotatable member, a recessed latch held radially andloose on the shaft close beside the said member in the path of one ofthe pegs of the slidable pin, the recessed part of the latch limitingthe possibility of engagement between latch and pin to the most extendedposition of the latter, a labyrinth of springy blades disposed on acertain sector only of the casing and forming a number of concentricpassages of a limited length for the second peg and constituting a guidefor this peg and for the sliding pin in order to bring the first peg inits most extend tures.

ed position in contact with the non recessed part of the latch and torelease this latch from its catch.

In testimony whereof We afi'lx our signa- ALFRED MAIRE. ARMAND BEGUELIN.

